Engine air cut-off device

ABSTRACT

The present invention provides an engine air cut-off device which can be connected into the manifold air passage of an internal combustion engine. The device includes a valve body having a passage therethrough which is alignable with the manifold air passage, the valve body incorporating a gate which is reciprocally mounted therein for movement between a retracted position in the body and a closed position which blocks the manifold air passage. The gate is provided with at least one integrally formed cylindrical bore which has a piston face at one end thereof. Means are provided in the valve body for introducing fluid underpressure into the cylindrical bore so that when the device is actuated the fluid under pressure will be introduced into the bore and will act against the piston face to drive the gate from its retracted to its closed position. Means are also provided for normally biasing the gate to its retracted position. The cut-off device of the present invention is very compact and is relatively simple to manufacture.

The present invention relates to an engine air cut-off device.

BACKGROUND OF THE INVENTION

It has been known in the past to provide fuel or air supply cut-offdevices for engines. For instance during the drilling of an oil or gaswell several operations are performed which may result in natural gasflowing into the enclosure around the operating engines and attaininghigh concentrations therein. Such natural gas could enter diesel enginesthrough the air intake and, even though the fuel oil is shut off, theengine could continue to operate. This would create hazards such assparks being emitted from the engine exhaust which could ignite the gasand air mixture around the engines and also the generous supply of fuelcould cause the engine to attain excessive speeds which could bedamaging to the engine itself. There have been prior attempts atproviding engine air cut-off devices, for example, reference can be madeto Canadian Pat. Nos. 587,457 (Oakes, Nov. 24, 1959); 788,333 (Gordon,June 25, 1968); or 914,644 (Verheul, Nov. 14, 1972). The cut-off devicesof these patents are probably effective in their own right but eachinvolves a structure which is large and unwieldy and which necessitatesa relatively complex actuation structure. In many instances externalactuation via a hydraulic or pneumatic cylinder is utilized or,alternatively, a spring biased type of actuation may be utilized.

SUMMARY OF THE PRESENT INVENTION

The present invention provides an engine air cut-off device whichovercomes many of the problems of the prior art. In particular thepresent invention utilizes at least one actuating piston, the actuatingpiston being incorporated into the gate of the shut-down device. Thus itis possible to achieve a compact device which is easily assembled andwhich is smooth in its actuation. In addition the present inventionprovides mechanism for accomodating minor misalignment between theoperating portions thereof, in particular between the elements whichconnect the source of pressurized fluid with the actuating piston andcylinder arrangements. Also, antivibration means are provided in thehousing of the present invention in order to reduce any wear or jammingpossibilities.

Broadly speaking, the present invention provides a cut-off device for anengine air manifold which comprises a valve body having a passagearranged for alignment with a corresponding passage in an enginemanifold, a gate reciprocally mounted in the body and having a path ofmovement across the valve body passage, the gate having a closedposition fully blocking the valve body passage and a retracted positionfully opening the valve body passage, means biasing the gate to theretracted position and means for moving the gate from the retractedposition to the closed position, the last-mentioned means including atleast one cylindrical bore in the gate parallel to the path of movement,conduit means sealingly engaging the bore and adapted to introduce fluidunder pressure into the bore and a piston face fixed in the bore againstwhich face the fluid may react to drive the gate from the retractedposition to the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of the engine air shut-off device of thepresent invention.

FIGS. 2 and 3 shows sections taken along the lines 2--2, 3--3,respectively in FIG. 1.

FIG. 4 is a partial section of the gate used in the present inventionand taken along the line 4--4 of FIG. 3.

FIG. 5 shows an enlargement of the rod end construction found in FIG. 2.

FIG. 6 shows a section along the line 6--6 from FIG. 7, illustratingclosed and open positions of a second embodiment.

FIG. 7 shows a section along the line 7--7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference is made to FIGS. 1 and 2 of the drawings wherein the engineair shut-off device 10 is shown. The device includes a main housing 12which has upper and lower portions 14 and 16 respectively held togetherby a plurality of nuts 18 and bolts 20 arranged around the periphery andextending through mating outwardly projecting flanges 22 and 24 of theupper and lower sections 14 and 16 respectively. Each of these upper andlower sections is provided with generally rectangular opening 26, theupper and lower openings being in direct alignment with each other.

As indicated above the device of the present invention is intended forinsertion in the manifold conduit or passage of an engine. To that endthe upper housing section 14 is provided with a plurality of outwardlyextending studs 28 arranged around the periphery of the upper opening26, the studs being adapted to be received in corresponding bores in aflange defining one end of a manifold conduit section. Bolts 30 arrangedaround the periphery of the lower opening 26 can be used to clamp theflanged end of a second conduit section to the lower housing section 16.Thus, when the openings 26 are not blocked there will be a free flow ofgases through the manifold conduits and the openings 26.

The openings 26 can be blocked by a reciprocable gate 32 which isreceivable in a chamber 34 defined between the upper and lower housingportions. When the gate is in the position found in FIG. 2 it blocks theopenings 26, thereby preventing the flow of gases along the manifoldconduit. Retraction of the gate into the chamber 34 permits the freeflow of gases through the conduits and the openings.

The gate is shown in greater detail in FIGS. 2, 3 and 4 wherein it isseen to have upper and lower surfaces 36 and 38 respectively, sidesurfaces 40 and a front end surface 42. Extending longitudinally of andbridging the distance between the upper and lower surfaces 36 and 38 arestrengthening ribs 44. Adjacent each side surface 40 are a pair ofsemi-cylindrical ribs 48 and 50 which define therebetween a cylindricalbore 52 parallel to the side surfaces 40. As seen in FIG. 4 the fowardend wall 42 which would normally close the cylindrical bore 52 has beenreplaced by a threaded plug 56 which is received in a threaded portionof the bore. End surface 42 is also provided with a plurality offorwardly projecting surfaces 46 which serve as stops for the gate whenit blocks passage 26. The gate stops engage similar projections 54 onthe valve body.

Spanning the upper opening 26 is a central rib 58 while a central rib 70spans the lower opening 26. The ribs 58 and 70 serve to strengthen thehousing in the vicinity of the opening.

FIGS. 2, 3 and 4 show in some detail the guiding mechanism for the gatewhich mechanism allows the gate to move into its blocking positionwithout contacting lower seal 74 (to be described hereinafter). Themechanism includes for each side of the gate, a guide strip 62 attachedto the inside of lower valve body 16 as by machine screws 64. At theforward end, the strip includes a depression 62a and at an intermediatezone it includes a second depression 62b Attached to each side of thegate, adjacent the front and rear surface are slide or guide pads 66aand 66b, respectively, connected to the gate as by machine screws 68.Pad 66a is longer than pad 66b and depression 62a is longer thandepression 62b, thereby avoiding the possibility of pad 66a droppinginto depression 62b as the gate is in its sliding mode.

FIG. 2 illustrates other aspects of the construction of the presentinvention. In particular O-ring type seals 60 and 74 are providedadjacent the upper and lower openings 26 respectively. The seal 74 is ina position such that it is contacted by the lower surface 38 of the gate32 when the gate is in its blocking position. The upper seal 60 providesa seal against gases which might result from a back-fire contact betweenthe upper surface 36 of the gate and seal 60 prevents such gases fromgetting past the gate and escaping through the engine's air filter tothe outside environment. Directly above the floor of chamber 34 is apressure block 78 contained in a cavity 80 within the upper housingsection 14. The block 78 may be retained within cavity 80 in anyconvenient manner, one of which could involve the use of a block 82 heldin place within the cavity 80 via a threaded bolt 84. Projectingforwardly of the block 82 could be a pair of arms 86 defining a spacetherebetween. Block 78 could have a "T"-shaped cross-section so that thearms of the "T" rest on the arms 86 with the leg of the "T" beingpositioned in the space between the arms and projecting downwardly. Adownwards bias may be provided by the compressions ring 88, againstwhich block 78 may be moved due to engagement of block 78 with the uppersurface 36 of the gate.

Conduit means are provided in order to supply fluid under pressure tothe cylinder bore 52, the means including a cylindrical rod 90terminating in an annular cup-seal 92 which is received in bore 52 witha sealingly slidable fit. Seal 92 is clamped between washers 72 and 76and held in place by a nut 76a threaded to the end of rod 90. Extendingthe length of rod 90 is a central longitudinal bore 94 whichcommunicates with the bore 52. At the opposite end of rod 90 to seal 92is a generally spherical enlargement 96 having an annular groove 98which receives an elastomeric seal 100. Enlargement 96 is received in acavity 102 formed in the back wall of lower body section 16, the cavityhaving an inner face 104 against which an O-ring seal 106 is forced byenlargement 96. A pivot washer 110, which may be formed ofpolytetrafluoroethylene, is held in position abutting the spherical endof rod 90 by a threaded plug 112, threaded into cavity 102. Finally, itis seen that enlargement 96 has a bore 114 therein which communicatescavity 102 with bore 94 in the rod 90.

A bore 116 in lower valve body 16 leads from cavity 102 to bores 118 and120 which eventually may be connected to the source of pressurizedfluid, with any type of conventional connection being suitable.

The above discussion has dealt with the structure which is utilized todrive the gate from its retracted position to the closed position andthis operation will be described more fully hereinafter. Drive forreturning the gate from the closed to the retracted position may beprovided by a pair of tension springs 122 anchored at one end to thefront wall 42 of the gate and at the other end to the back wall of thelower housing section 16. Each spring would pass along the appropriatecavity formed in the gate by walls 40 and 48.

The operation of the present invention will now be described.

In a non-emergency situation the gate 32 is held in its retractedposition in the chamber 34. The gate is held in this position by thetension springs 122 as well as by the biasing forces provided by thebiasing block 78. Vibration of the gate is, of course, greatly reducedthrough the biasing action of the block 78 towards the floor of section16 causing tight engagement of pads 66a and 66b against guide strip 62.When an engine emergency is detected remote from the device of thepresent invention an actuating fluid under pressure is introduced intothe two cylinders 52. The fluid under pressure passes through the bores120 and 118 in the lower body section 16 into cavity 102 and through thebore 114 to bore 94 in rod 90. The fluid under pressure thus passesalong bore 94 into the cylindrical bore 52 and acts against the plug 56.The increase in pressure in the cylindrical bore 52 drives the gate fromits retracted position to the closed position wherein it blocks theopenings 26 to thereby restrict the flow of induction gases through themanifold conduit, hence stopping the engine. The movement of the gate 32is dampened via spring forces and when the gate is in its closedposition it is sealed with respect to the manifold conduit via O-ringseal 74. If the seal were not provided by the O-ring 74 induction gasescould pass by the gate and thereby prevent a total shut-down of theengine.

Once the emergency situation has been overcome the pressure transmittedby the fluid is reduced and the tension springs 122 are thereby able toexert their restoring forces whereby the gate is moved from its closedposition to its retracted position.

It is therefore seen that the present invention provides a veryeffective engine shut-off device which is especially compact in naturedue to the incorporation of the pressure cylinders 52 into the gate 32as an integral part thereof. The overall device is of a relativelysimple nature and is easily manufactured. Provision has been made toensure that there will be a minimum of wear during operation of thedevice and in addition care has been taken to ensure that the movingparts of the apparatus are well guided and hence the chances of ajamming condition are greatly reduced.

In addition to the above advantages it is seen that the resilientmounting of rod 90 in the lower body section 16 in combination with theresilient seal surrounding rod 90 in bore 52 permits some angularmisalignment of rod 90 with respect to the gate without hindering theoperability of the gate.

A second, simpler version of the present invention is illustrated inFIGS. 6 and 7. This particular embodiment is useful in engines havingsmaller diameter intake ducts and may be especially useful in mobilerather than stationary power plants.

FIG. 6 shows a section along the line 6--6 of FIG. 7, the portion ofFIG. 6 above the center line showing the gate retracted and the lowerportion of FIG. 6 showing the gate in its blocking position. The valveincludes a valve body 124 having a passageway 126 therethrough for thenormal passage of engine gases. Means (not shown) may be employed to fixthe valve body in an appropriate location on the engine manifold.

Valve body 124 has a central cavity 128 which is generally rectangularin plan and elevation but has rounded, semi-circular ends in plan, theradius of the end portions being greater than that of passageway 126whereby shoulders 130 is created about the circumference of passageway126.

Located within cavity 128 is the gate 132 which is generally circular inplan having upper, lower and circumferential surfaces 134, 136 and 138respectively. Extending axially of the gate is a cylindrical wall 140defining a bore 142 therein. Wall 140 extends beyond the circumferentialwall 138 as at 144 and the extension has a bevelled inner edge 146. Atthe opposite end bore 142 is plugged by a plug member 148 which may beheld in place by interengaging threads. Extension 144 is adapted to restwithin a circular cavity 150, extending into the valve body 124 from themain central cavity 128.

Valve body 124 is also provided with an external extension 152 which inturn has a bore 154 communicating with cavity 150. A circular recess 156is formed within extension 152 so as to open out onto bore 154. Bore 154receives an annular conduit or rod 158 having an internal bore 160, rod158 extending into cavity 128 a distance approximately equal to thelength of bore 142. As seen from both FIGS. 6 and 7 when the gate isretracted rod 158 will be positioned within bore 142.

Internally, rod 158 carries a helical tension spring 162 which isanchored at one end to the gate plug 148 and at its other end to anabutment 164 held within rod 160. Abutment 164 is formed and positionedso as to cause minimum interference to fluids flowing in bore 160.

Since the cut-off device of the present invention is used to cut-off gasflows and since it depends on pressurized fluid for actuation it isnecessary to provide sufficient sealing. Thus gate 132 is provided withO-ring seals 164 and 166 in the top and bottom surfaces 134 and 136respectively. When the gate is in the blocking position seals 164, 166will be able to contact shoulders 130, 130 to prevent gases from blowingby the gate. Rod 158 is sealed with respect to gate bore 142 by anannular resilient cup seal 168 held in place by a pair of annularmembers or washers 170 affixed to the rod 158.

Other resilient members utilized include an O-ring bumper 172surrounding rod 158 at the end of cavity 150 and adapted to engagebevelled edge 146 of gate extension 144 to prevent contact betweenextension 144 and the cavity end wall. Also utilized is a pair ofO-rings 174 positioned in recess 156 on either side of a washer member176 affixed to rod 158. This permits rod 158 to be generallyself-aligning with bore 142, thereby permitting slight movement of rod158 without interfering with the operability of the gate.

The principle of operation of this embodiment is essentially the same asfor the first embodiment. When necessary to block the passageway 126fluid underpressure, such as compressed air is introduced into bore 160of rod 158 to act on plug member 148. The forces produced by thepressurized fluid drive the gate from its retracted position (upperportion of FIG. 6) to its blocking position (lower portion of FIG. 6).In the blocking position spring 162 is stretched and hence when thefluid pressure is relaxed the spring forces will retract the gate to itsrest position. The above description is intended to relation to bestmode of putting the present invention into effect. It is certainlyrecognized that other practioners in the art may deviate from the exactstructure as indicated above without departing from the spirit ofinvention. Other alternative constructions are possible without alertingthe spirit of the invention. The scope of protection to be afforded thepresent invention is to be determined only from the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A cut-off device for anengine air manifold which comprises a valve body having a passagearranged for alignment with a corresponding passage in an engine airmanifold, a gate reciprocally mounted in said body and having a path ofmovement across said valve body passage, said gate having a closedposition fully blocking said valve body passage and a retracted positionfully opening said valve body passage, a pair of guide strips in saidvalve body extending parallel to said path of movement adjacent saidvalve body passage, there being one guide strip for each edge of saidgate, each strip having a pair of longitudinally spaced apartdepressions in an upper surface thereof, one depression being longerthan the other, a pair of spaced apart guide pads mounted on each edgeof said gate for sliding movement on the guide strip adjacent thereto,one of said pads being longer than the other of said pads whereby whensaid gate is in its closed position the longer pads engage the longerdepressions of the guide strips and the other pads engage the otherdepressions of the guide strips, means biassing said gate to saidretracted position and means for moving said gate from said retractedposition to said closed position, said last-mentioned means including atleast one cylindrical bore in said gate parallel to said path ofmovement, conduit means sealingly engaging said bore, forming a pistonface within said bore and including means for introducing fluid underpressure into said bore through said conduit means, and a plug closingone end of said bore and defining a piston chamber between said plug andsaid piston face, whereby said fluid under pressure will react againstsaid piston face and said plug to drive the gate from the retractedposition to the closed position.
 2. The cut-off device according toclaim 1 wherein said valve body includes a hollow chamber therein forreceiving said gate in said retracted position and a spring biasedvibration damper in said chamber for engaging one side of said gate whensaid gate is in said retracted position.
 3. The cutoff device of claim 1and including seal means adjacent the periphery of said valve bodypassage and engageable with said gate in the closed position thereof toprevent leakage of gases past said gate.
 4. The cut-off device of claim3 wherein said seal means includes a first resilient sealcircumferentially positioned with respect to said valve body passage forengagement with one surface of said gate and a second resilient sealcircumferentially positioned with respect to said valve body passage forengagement with the other surface of said gate.
 5. The cut-off device ofclaim 1 wherein said valve body includes a hollow chamber therein forreceiving said gate in said retracted position, said conduit meansincluding a hollow rod located in said chamber, with one end thereofsealingly engaging said bore and the other end thereof being mounted inalignment compensating means connectable to a source of said fluid underpressure said compensating means maintaining said rod in alignment withsaid bore during reciprocal movement of said gate.
 6. The cut-off deviceof claim 5 wherein said compensating means includes an annularenlargement on said rod and a pair of resilient mounting members locatedin a cavity of said valve body, said enlargment being positioned betweensaid mounting members.
 7. The cut-off device of claim 5 wherein saidcompensating means includes a bulbous enlargement of said rod positionedin resilient sealing and mounting means in a cavity within said valvebody.
 8. The cut-off device of claim 7 and including a bore in saidenlargement communicating said cavity with the hollow interior of saidrod, and means communicating said cavity with said source of fluid underpressure.
 9. The cut-off device of claim 1 wherein said biasing meanscomprises at least two tension springs, each connected at one end tosaid gate and at the other end to said valve body.
 10. A cut-off devicefor an engine air manifold comprising a valve body having a passagearranged for alignment with a corresponding passage in an engine airmanifold, a cavity in said valve body opening into said valve bodypassage, a gate movably contained in said valve body and having a pathof movement across said valve body passage, said gate having a closedposition fully blocking said valve body passage and a retracted positionin said cavity fully opening said valve body passage, a pair of guidestrips mounted in said valve body adjacent said passage and parallel tosaid path of movement, these being one guide strip for each side of saidgate, each strip having a pair of longitudinally spaced apartdepressions in an upper surface thereof, one depression being longerthan the other, a pair of spaced apart guide pads mounted on each sideof said gate for sliding movement on the corresponding guide strip, oneof said pads being longer than the other of said pads whereby when saidgate is in its closed position the longer pads engage the longerdepressions and the shorter pads engage the shorter depressions, a pairof tension springs connected between said gate and said valve body tobias the gate to its retracted position, a pair of cylindrical bores insaid gate parallel to said path of movement, a conduit for each of saidbores mounted in said valve body and extending into and sealinglyengaging the corresponding bore, each of said conduits forming a pistonface within the corresponding bore, and including means to introducefluid under pressure into said corresponding bore through said conduitand each bore having a plug closing one end thereof to define a pistonchamber between said corresponding plug and said corresponding pistonface whereby said fluid under pressure will react against the pistonfaces and the plugs to drive the gate from the retracted position to theclosed position.
 11. A cut-off device for an engine air manifold whichcomprises a valve body having a passage arranged for alignment with acorresponding passage in an engine air manifold; a gate reciprocallymounted in said body and having a path of movement across said valvebody passage, said gate having a major surface which in a closedposition of said gate fully blocks said valve body passage and said gatehaving a retracted position wherein said valve body passage is fullyopened; said valve body including a hollow chamber therein for receivingsaid gate in said retracted position; spring biassed vibration dampingmeans mounted in said chamber for engaging said major surface of saidgate and biasing said gate toward a floor of said chamber when said gateis in its retracted position within said chamber; means biassing saidgate to said retracted position within said chamber; and means formoving said gate from said retracted position to said closed position,said last-mentioned means including at least one cylindrical bore insaid gate parallel to said path of movement, conduit means sealinglyengaging said bore, forming a piston face within the bore and includingmeans for introducing fluid under pressure into said bore through saidconduit means, and a plug closing one end of said bore and defining apiston chamber between said plug and said piston face, whereby saidfluid under pressure will react against said piston face and said plugto drive the gate from the retracted to the closed position.